dinosaur of the day

Chaoyangsaurus youngi

By Jack Wood on @thewoodparable

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Name: Chaoyangsaurus youngi

Name Meaning: Chaoyang Reptile

First Described: 1999

Described By: Zhao, Cheng, & Xu

Classification: Dinosauria, Ornithischia, Genasauria, Neornithischia, Cerapoda, Marginocephalia, Ceratopsia

Chaoyangsaurus is an early derived Ceratopsian from the Late Jurassic, approximately 148 million years ago in the Tithonian age. As such, it is another representative of the earliest members of the Ceratopsian group, and thus shows what the most basal members were like. It was found in the Tuchengzi Formation in Liaoning, China, and is known from a partial skeleton what only includes part of the skull. It probably would have been only about a meter long. 

Sources:

https://en.wikipedia.org/wiki/Chaoyangsaurus

https://en.wikipedia.org/wiki/Tuchengzi_Formation

Shout out goes to @serpentgodoftheskies!

3

Happy Father’s Day to all fathers, step-fathers, adopted fathers, grandfathers, and father figures, who teach us to be strong, to be ourselves, and to love. This is for the hugs and kisses, for the support and encouragement, and for the love our fathers give us.

Tyrannosaurus rex

Source: http://archive.4plebs.org/tg/thread/24671314 (Note: It probably would not have had pennaceous feathers) 

NameTyrannosaurus rex 

Name Meaning: Tyrant Lizard King

First Described: 1906

Described By: Osborn

Classification: Dinosauria, Saurischia, Eusaurischia, Theropoda, Neotheropoda, Averostra, Tetanurae, Orionides, Avetheropoda, Coelurosauria, Tyrannoraptora, Tyrannosauroidea, Tyrannosauridae, Tyrannosaurinae, Tyrannosaurini 

Tyrannosaurus rex. This is the name that everyone has associated with dinosaurs since before most readers of this blog can remember. It is the embodiment of power, terror, real-life monsters, and everyone - I mean everyone - has an opinion about it. So what can I tell you here that you do not already know? Well, I can tell you a lot, actually. And I can also tell you what you already know just for posterity’s sake. But first, two things to get off the bat here:

1. It is T. rex or Tyrannosaurus rex. t rex, T-rex, and variations thereopn are incorrect. You see, Tyrannosaurus is the genus name; rex is the species name (much as for humans it is Homo sapiens). And in phylogenetics, the genus and species names for an organism are always in italics (if possible). Furthermore, the genus name is always capitalized; the species name is not capitalized. Finally, oftentimes it is useful to shorten the name to just the genus initial and the full species name; when you do this, you put a period after the genus initial, a space, and then the species name. Hence, the hyphen of the completely incorrect T-rex is out of place, just for one example. It is Tyrannosaurus rex, TyrannosaurusT. rex, or nothing. 

2. Based on fossil evidence, it is most likely that Tyrannosaurus had feathers, given the prevalence of feathers in its evolutionary tree and the early evolutionary position of feathers in Dinosauria. Given that, I admit that it is a valid argument to say that Tyrannosaurus might have been too big for full body feathers; however, in paleontological and biological studies of trait evolution, it is always Occam’s Razor: the simplest explanation is true. And thus, since T. rex’s ancestors definitively had feathers, it is simpler for T. rex to have had feathers than for it to have not (its more complicated to lose a trait than to keep it); furthermore, similar sized animals  have been found completely with feathers, or with feathers and scales, so size isn’t much of an issue here. In short, until we have direct evidence that Tyrannosaurus rex wasn’t feathered (and right now, we do not), we must say that it was; much as we must say that early primates had fur, since mammals ancestrally have fur, even though we do not have a lot of fur fossils for early primates. I will hear no more argument on the subject, especially non-scientific (“Feathers make T. rex uncool!”) arguments. 

Source: https://whendinosaursruledthemind.wordpress.com/2014/12/23/when-dinosaurs-ruled-the-mind-36-dinosaurs-over-the-years-tyrannosaurus/

Now that we’ve gotten that out of the way, let’s get down to business. Tyrannosaurus lived in the Maastrichtian age of the Late Cretaceous period, 68 to 66 million years ago, right up until the end of the Mesozoic Era (hence, almost ever dinosaur documentary ends with them, and there’s the classic image of T. rex against a giant asteroid falling from the sky). It has been found all over Western North America, from Colorado to Wyoming to South Dakota to Montana. It has been famous since its discovery, due to its size and relatively terrifying stature. It is also known from over 30 specimens, however these specimens are not all complete, and what we know about T. rex is based on a cross examination of all individuals. It probably reached a maximum length of 13 meters long and 4 meters tall, making it about 6.8 metric tons in weight. It was the largest carnivore in its environment, but not the largest carnivore of all time or the largest carnivorous dinosaur; Spinosaurus holds that second title. But, Spinosaurus basically only lived in the water, so it really is a silly question to ask who would win that fight. It’s comparing apples and oranges. 

Source: http://io9.com/now-this-is-a-badass-feathered-tyrannosaurus-rex-1605638011

Tyrannosaurus, like others of its family tree, had a fairly unusual skull for a theropod. It had binocular, good vision; a deep skull, and a short snout. The nasal bones and some others were fused but had a honeycomb of tiny air spaces, making them both stronger and more flexible and light. It had, as a result, an extremely powerful bite, exerting an extreme amount of force in a wider area due to the U-shape (rather than V-shape) of its upper jaw. It is possible, as a result, that it had the strongest bite force of any terrestrial animal known, with up to 23.5 metric tons in the highest estimates. It had marked heterodonty in its teeth, with closely packed teeth at the front of the upper jaw, with serration as well as a curved shape. This would allow them to stay intact when the T. rex bit down on struggling prey. Furthermore, the back teeth were robust, more robust, and reinforced. The teeth could get up to 30 centimeters in length, the largest tooth of any carnivorous dinosaur known. 

Source: https://whendinosaursruledthemind.wordpress.com/2014/12/23/when-dinosaurs-ruled-the-mind-36-dinosaurs-over-the-years-tyrannosaurus/

Many specimens have been found, as stated, and as such we know a lot about this dinosaur’s life history and traits. Like humans, tyrannosaurs in general grew moderately in early life and later life, with an extreme period of rapid growth in their teens. Furthermore, Tyrannosaurus, as opposed to other members of its family, had extreme growth in the teenage years, gaining an average of 600 kg a year, allowing it to go from 1,800 kg as a juvenile to 6,000 kg as an adult in just four or so years (talk about a pubescent growth spurt, am I right?) In fact, as such, as juveniles Tyrannosaurus young would have been fairly similar to other members of the tyrannosaurid family group, only distinguishing itself in size and stature after this period of rapid growth. This growth also brought about sexual maturity (woo, puberty for T. rex), though most tyrannosaur specimens known died long before this point, as many long-lived animal species show in the past and today. However, sampling bias plays a high role in age-group fossilization representation, and as such the relative mortality rates for T. rex at different life stages cannot be conclusively stated. 

Source: http://www.buzzfeed.com/mathieus/how-t-rex-really-looked-like-8q4

Sexual dimorphism has been seen in the species, given the presence of two distinct body types amongst fossils. The robust morph also had a wider pelvice, indicating that this form would have belonged to the female to allow for the passage of eggs. However, recently the evidence for dimorphism has been weakened due to the idea that certain differences could be based on location, rather than sex. One specimen, however, dubbed B-rex, was found with soft tissue, some of which identified as medullary tissue, which in modern birds is used as a source of calcium for eggshell production. This indicates that B-rex was a female and died during ovulation, and as this is not found in crocodiles, is another link between birds and dinosaurs. 

Source: http://modgenesis.forumlaunch.net/viewtopic.php?p=144121&sid=6735e83c97ac7b7bffd76b4d247a9e4c

T. rex is often made fun of for the size of its arms, though as long term fans of this blog know, it didn’t have the smallest arm to body ratio for dinosaur by any stretch of the imagination (remember the month of the abelisaurs? I do.) The arms of T. rex were 1 meter long (which was short compared to its body, as I’m sure you’ve figured,) and could have assisted T. rex in rising itself from a lying down position. It also could have been used to grip down on struggling prey while T. rex tried to kill it with its jaws, which has been supported by analysis of the mechanics of the arms. It would have been able to lift 199 kg in its arms without the help of other muscles, making its actual lifting power about 3.5 times as strong as a human of the same size would be. The arm did have a limited range of motion though, but that would allow the prey to hold still, aiding T. rex in finishing the kill with its crunching jaws. 

Source: https://whendinosaursruledthemind.wordpress.com/2014/12/23/when-dinosaurs-ruled-the-mind-36-dinosaurs-over-the-years-tyrannosaurus/

It is still relatively unclear whether T. rex was warmblooded or coldblooded (endothermic or ectothermic, respecitvely). High growth rates in the animal’s youth, combined with lower growth rates as an adult, are similar to patterns in birds and mammals, indicating endothermy. Furthermore, studies have been done using the Oxgyen isotope ratios in the fossilized bone to determine the temperature of the bone when it was deposited, which can correlate with body temperature. The temperature has been found to not vary much across the body, indicating a constant internal body temperature and a metabolism somewhere between ectothermy and endothermy. This has been corroborated by similar patterns in other dinosaurs but wide variation in lizards and other, less bird-like reptiles. However, this only proves homeothermy - constant body temperature - and does not indicate if it was endothermic through metabolism or gigantothermic through the size of the animal, which can help to maintain body temperature. 

Source: http://nebezial.deviantart.com/art/Winter-Kill-345624627

The locomotive abilities of Tyrannosaurus have long been under debate, especially its maximum speed and its turning abilities (much like one’s main concerns when deciding in Mario Kart.) It was probably slow to turn, taking 1 to 2 second to go 45 degrees, an amount that humans do in about a fraction of a second. This was due to T. rex's center of mass being far away from its center of gravity, giving it terrible rotational inertia (physics, my nemesis, how are you.) The maximum speed is under considerable more debate. This is thanks to the convenient lack of running tracks for T. rex, or any theropod, making it hard to know its speeds definitively. Its been called slow (Jack Horner and Don Lessem), and its been called fast. I, and most others, spent our childhood being told practically every other year something different, so here’s a little timeline. 

  • Traditionally, hollow bones and other features may have kept the body of T. rex relatively light, allowing it to have long, flexible legs with high speeds; furthermore it had large thick leg muscles, giving more power to faster running up to 40-70 km per hour
  • 1993 Jack Horner and Don Lessem argued that it was actually slow, because its ratio of femur to tibia length was >1, like in modern elephants, who cannot run. 
  • 1995 Farlow et al. argued that it would have been fatally injured when moving quickly, the torso of the animal slamming into the ground at 6 Gs (six times the acceleration due to gravity) and the arms would not have reduced the impact. However, giraffes actually face similar problems, making it possible that T. rex ran when necessary despite the risks. 
  • 1998 Holtz describes that the distal hindelimb components (shin, feet and toes) were much longer relative to the femur, and that inconjuction with tightly interlocked foot bones transmitted the locomotion force from the foot to the lower leg better than in earlier theropods, allowing faster speeds 
  • 1998 Christiansen figured that the leg bones of Tyrannosaurus were not that much stronger than those of elephants, and thus the maximum speed of T. rex was about 11 meters per second… but a lot of this was based on dubious assumptions. 
  • 2000 Gregory S. Paul pointed out that the flexed kneed and toes were better designed for running in T. rex than in humans or elephants, and the reduced risk of getting hurt fighting would have outweighed any risk in actually running. 
  • 2002 a paper in Nature used math to find that anything above 40 km/hr would have required extremely large leg muscles, up to 40-86% of the body mass, and even moderately fast speeds would have required large leg muscles. It is unsure, therefore, what the top speed was, as we do not know how big the leg muscles were. 
  • 2003 Snively and Russelfound that the toe bones and ligaments there could work together in a ‘tensile keyestone model’ to strengthen the foot, keeping it stable and resistant, storing the strain energy through the use of these arctometatarsals (hello physics, my old friend.) This woul dhave given it greater agility than other large theropods without this feature. 
  • 2007 More computer models estimated a top speed of 29 km/hr, based on solely fossil data
  • 2010 Scott Persons proposed that the speed was enhanced through tail muscles, assisting in leg retraction and ehancing running ability, agility and balance. The tail was further adapted for large muscle mass growth, with the muscle that would balance the leg in question making up as much as 58% of the tail’s muscle mass, giving it a closer center of mass and gravity, improving balance and agility, and also making it less front heavy and decreasing its rotational inertia. 
  • 2011 Mallison proposed that it used short, rapid strides rather than long strides like modern birds and mammals in order to run faster, making it more like power-walking, lessining the need for additional muscles in the legs. This also makes it harder to calculate stride length, as it cannot be measured the same as one does in birds and mammals. However, this depends on how frequently dinosaur muscles could contract, something we don’t know much about. 
  • Even if T. rex could not run, it could get to about 17 km/hr, which is still faster than most hadrosaurids and ceratopsians (provided you agree that ceratopsians are slow, which is actually under debate), its main prey species. It was also much longer than the animals it hunted, further aiding in prey capture. 

In short, I would pick another cart, just in case. 

Source: http://pheaston.deviantart.com/art/Tyrannosaurus-rex-327093489

Tyrannosaurus rex had keen vision, with a binocular range of 55 degrees, surprising that of modern hawks, and 13 times the visual acuity of humans, allowing it to discern objects as far away as 6 kilometers. It needed this keen depth perception to figure out where the horns and spikes of armored dinosaurs, such as ankylosaurids and ceratopsians, jutted out, allowing it to get in and kill the prey in the most efficient and safe manner possible. Its visual acuity was not based on movement and honestly I have no idea how Jurassic Park got away with that. It also had an heightened sense of smell, allowing the animals to detect carcasses by scent alone across great distances, and in fact T. rex probably had the most heightened sense of smell of any known non-avian dinosaur. It also had high hearing acuity, hearing best in the low-frequency range, which probably facotred a lot in behavior. It had one of the largest brains of all adult non-avian dinosaurs with the exception of some maniraptoriforms, but still in the range of modern reptiles and lower than that of modern birds - but close to that of alligators. 

Source: http://phenomena.nationalgeographic.com/files/2013/12/tyrannosaurus-rex-conway-1024x1024.jpeg

You know what people like to argue about as much as they like to argue about T. rex locomotion? Its predator or prey habits. Hoo boy. Jack Horner has long been a proponent of the scavenger theory, citing the short arms that could not be used to grip prey (which, as we’ve learned, actually could grip prey,) heightened sense of smell which is common in modern day scavengers like vultures to allow for the sniffing out of carcasses, the ability for T. rex teeth to crush bone, to get more nutrition from bones in a carcass, and of course, its speed being too slow to catch prey. However, as we’ve already learned, a lot of these points aren’t very convincing, and in fact, there is also evidence for hunting behavior. Binocular vision like hawks would allow for the ability to hunt better, and in modern animals binocular vision is mainly found in predators. Furthermore, an Edmontosaurus skeleton has been found with damage healed on its tail vertebrae, indicating that the T. rex attacked it when alive. There has also been evidence found for interaction between Triceratops and Tyrannosaurus. However, if Tyrannosaurus had been a scavenger, then the smaller predators of the area would have been the apex predators (such as troodontids,) and the size of T. rex would have allowed it to steal kills from them. Like most larger carnivores, T. rex probably engaged in an opportunistic mixture of both. It may or may not have an infectious bite like Komodo dragon, but this is under debate, and it probably processed kills through lateral shakes of the head. 

Source: http://luisvrey.files.wordpress.com/2012/06/t-rex-offspringb.jpg (Note: The mom should also have feathers)

There is some evidence for pack behavior in Tyrannosaurus, given finds in which multiple individuals were found together and the possibility of pack behavior in other tyrannosaurids. Given its large brain to body size ratio, it also was smart enough for complex behaviors, and groups would have worked together to take down well armored prey. Furthermore, trackway evidence in Canada has indicated that tyrannosaurs may have hunted in groups. There is not a whole lot of evidence about behavior out there, however, in the fossil record, and while there are many opponents of the pack hunter theory, their evidence is as scarce as the pro position. It might have had a sort of halfway point between pack hunting and solitary hunting, forming groups when convenient. Furthermore, little evidence is present for or against nesting behavior, which I find frustrating; while many species of dinosaurs took care of their young, many others did not. I’m inclined to think, based on their large brain size and close relationship to birds, that Tyrannosaurus did care for its young in some capacity; however, more research needs to be done before it can be scientifically analyzed. 

Source: http://img3.wikia.nocookie.net/__cb20140110005309/dinosaurs/images/6/68/New_tyrannosaurus_test_render_project_mesozoica_by_sketchy_raptor-d6wv444.png

Tyrannosaurus lived in a complex, but not very diverse community of dinosaurs. At the end of the Cretaceous, dinosaurs were already dwindling in diversity due to a complex interplay of environmental factors. This contributed, in the end, to the extinction of non-avian dinosaurs at the end of the Cretaceous; they were already significantly less diverse, and it did not take much to finish off the rest. It lived alongside Triceratops, the sauropod Alamosaurus, and other herbivores such as Torosaurus, Edmontosaurus, Ankylosaurus, Pachycephalosaurus, Thescelosaurus, and the theropods Ornithomimus and Troodon. In its southern range, it also has lived alongside Struthiomimus and LeptoceratopsGlyptodontopelta, and Quetzalcoatlus. It lived in a warm and humid suptropical climate, alongside the Wetern Interior Seaway. It can be supposed that it went extinct with the asteroid impact at the K-T boundary. As we all know, Tyrannosaurus rex is a really famous dinosaur; and as such, its reference in pop culture are practically infinite. 

Sources: 

https://en.wikipedia.org/wiki/Tyrannosaurus

http://www.prehistoric-wildlife.com/species/t/tyrannosaurus.html

Velociraptor mongoliensis, V. osmolskae

Source: artisticthingem

Name: Velociraptor mongoliensis, V. osmolskae 

Name Meaning: Swift Thief

First Described: 1924

Described By: Osborn

ClassificationDinosauria, Saurischia, Eusaurischia, Theropoda, Neotheropoda, Averostra, Tetanurae, Orionides, Avetheropoda, Coelurosauria, Tyrannoraptora, Maniraptoriformes, Maniraptora, Pennaraptora, Paraves, Eumaniraptora, Dromaeosauridae, Eudromaeosauria, Velociraptorinae

Other Accepted Names: Pointy Birb 

My Thirteenth Favorite Dinosaur!

Velociraptor is a fairly famous dinosaur thanks to the Jurassic Park franchise. Except, the dinosaurs in Jurassic Park called raptors? Not really Velociraptors. If the above illustration doesn’t demonstrate this, perhaps my description will. Velociraptor was a small dromaeosaurid dinosaur, about 2 meters long and less than one meter high. In fact, it would have stood up to about one’s thigh on a somewhat tall person (1.8 meters, or 5′11″). This makes it about the size of a coyote. It lived in the Campanian age of the Late Cretaceous, about 75 to 71 million years ago, making it fairly far removed from the famous Tyrannosaurus rex of Jurassic Park (so the scene at the end of the film definitely never actually happened.) It is known from many specimens, making this one of the best known non-avian dinosaurs (and the best known dromaeosaur), making it quite weird that this dinosaur’s name was used to describe the thematic monsters, when it definitely was nothing like them. 

Source: http://phenomena.nationalgeographic.com/2013/03/20/a-velociraptor-without-feathers-isnt-a-velociraptor/

Velociraptor was found in both the Barun Goyot Formation and the Djadochta Formations of Mongolia. It is one of those dinosaurs that, without question, had feathers (and, thus, any interpretation without feathers is unequivocally incorrect). It has been found with quill knobs on the fossil where feathers would have been held, especially on the arms; these knobs cannot be interpreted as anything else. This is in conjunction with main close relatives of Velociraptor having been found with feather impressions; the small size of the animal (making size-related secondary loss of the structures unlikely); and the close relationship with modern birds. Though no direct feather impressions have been found with this dinosaur, there isn’t much more they could tell us than what has already been found. 


Source: http://en.wikipedia.org/wiki/Velociraptor

The skull of Velociraptor had a slight up-curved, concaved upper surface, and it was fairly elongated, rather than box-like. It had large hands with strongly curved claws much in the same flexibility and shape as the wings of modern birds. This indeed helps lend knowledge as to the shape of the wings of this animal - it had 14 secondary feathers on the forearm, with remiges on the second finger. It couldn’t fly, so the animal used its feathers for different purposes, such as display, covering their nests, and for added speed when running, as well as insulation. Given the wide variety of uses feathers have with birds besides flight, this is not particularly surprising. Furthermore, it had to hold its hands in a wing-like position; pronation (holding the hands in a way so the palm faces the ground or backwards towards the legs) was impossible, like in all theropods. In addition, Velociraptor, like the other members of its family, had an enlarged second toe claw on its feet, the famous sickle-claw that was probably used to restrain or stab into struggling prey. The sickle claw of Velociraptor was 6.5 centimeters long. 

Source: http://olorotitan.deviantart.com/art/Velociraptor-and-protoceratops-160584261

Velociraptor had bony projections on the top of the tail vertebrae and tendons underneath. This is similar to other dromaeosaurs and were thought to stiffen the tail, allowing it to serve as a rod for balance. However, one specimen has been found with the intact vertebrae curved into an S-shape, indicating the tail was slightly more flexible than assumed. This animal has been found in a variety of interesting poses: the first fossil was a crushed and complete skull associated with the famous toe claws; however the most famous find of this dinosaur is the “fighting dinosaurs” specimen, in which a Velociraptor and a Protoceratops (shown in the above image) were found together in a battle pose, and is considered a national treasure of Mongolia. This fossil shows not only that Velociraptor was a predator, but also that it preyed upon equal-sized animals in its habitat. 

Source: http://www.hellokids.com/c_28262/drawing-for-kids/drawing-tutorials-step-by-step/dinosaurs/how-to-draw-raptors

The claw was probably used to stab prey as well as restrain, rather than slash as is popularized. It is only sharp at the point, rather than along the inside, making slashing rather difficult. The fighting dinosaurs find also had the claw in a position in which it looked like it was stabbing at the neck of the Protoceratops, which would have allowed for both the carotid artery and Jugluar veins to be severed, destroying an important blood line between the brain and the heart. The Protoceratops, if the fight had continued, would have been dead fairly quickly. This find was preserved in sand dune deposits, indicating that the two were buried in sand that had rapidly fallen on them, either from a collapsing dune or a sandstorm. They were rapidly buried, preventing the lifelike pose of the animals from being disturbed, though parts of the Protoceratops are missing, indicating that scavenging did occur. 

Source: http://scotthartman.deviantart.com/art/Velociraptor-in-cape-hunting-dog-garb-353735722

Velociraptor (and Protoceratops) lived in an arid climate, with fields of sand dunes and intermittent streams, though the Barun Goyot environment was slightly wetter than the Djadochta. Many specimens of Velociraptor were in fact buried alive in the sand, in addition to the fighting dinosaurs. It lived alongside many types of dinosaurs: Protoceratops, Pinacosaurus, Sauronithoides, Oviraptor, Mahakala, Magnirostris, Machairasaurus, and Linheraptor, making it one of many predators from the region. Velociraptor may also, in addition to piercing vital organs with its claw, jumped on top of prey and pinning it down, gripping it with the sickle claws to restrain it, like certain birds of prey. This idea is especially strengthened through the similarity of the legs and arms to eagles and hawks, and the similarity of foot strength to owls. The arms could have been used to stabilize the animal through flapping, along with the stiff tail. The jaws were fairly weak, however they could have been used in a sawing motion, like in the Komodo Dragon, to finish off the prey of the kicks were not doing the trick. This flapping motion when hunting prey could have been one of the reasons it evolved in paravians, leading to the evolution of flight. 

Source: http://julio-lacerda.deviantart.com/art/Velociraptor-mongoliensis-243615132

Velociraptor may also have been a scavenger, with tooth marks found on a Protoceratops jaw bone, which is not the most ideal part of the carcass for Velociraptor to eat and, thus, would have only been eaten if nothing else was present. However, it having scavenger behavior just makes it an opportunist; hunting and scavenging when need be to get the right amount of food. It was probably warm-blooded, needing significant energy to hunt; the presence of a feathery coat also reinforces warm-bloodness. However, its growth rate, as determined by bones and references to modern day animals, indicate a more moderate warm-blooded metabolism, like that of the kiwi bird. The kiwi is highly active, with a stable body temperature and a low metabolic rate; which is probably similar to that of Velociraptor

Source: http://dinosaurrevolution.wikia.com/wiki/Velociraptor

Velociraptor is commonly depicted as a pack hunter, however this is relatively unfounded; it hasn’t been found closely associated with other individuals, as would be expected for this sort of behavior. Furthermore, other dromaeosaurs also have limited evidence for pack behavior in fossil findings, with the very idea only based off of the finding of several Deinonychus found with a Tenontosaurus. If Velociraptor did form packs, they were not organized or permanent. This makes sense, given that they lived in a desert; resources such as food and water would have been scarce, and a “it’s every raptor for themself” mentality would have been the best survival strategy. Thus, social behavior in Velociraptor is relatively unknown, and it probably was a solitary creature; though whether or not it cared for its young is unknown. 

Source: http://emilywilloughby.com/gallery/paleoart/the-velociraptor-hunting-dance

When it comes to intelligence, Velociraptor was a dromaeosaurid, which is a fairly smart group of dinosaurs when compared to other dinosaurs; they had large brain-to-body mass ratios, or EQs. In fact, one of the major features of avian evolution is the growth of that EQ ratio, with birds having much larger brains than non-avian dinosaurs in general (and a general trend going from reptilian to avian intelligence levels). However, it was not nearly as smart as depicted in popular culture; the smartest known non-avian dinosaur, Troodon, only had 31.5% to 63% change from reptilian to avian intelligence brain proportions. Velociraptor had a much smaller brain-to-body ratio, making it much less intelligent than modern birds, and no where near smart enough to, say, set an elaborate trap, or open doors. However, it was a smart dinosaur, giving it a leg up in its prehistoric world. 

Source: http://vitor-silva.deviantart.com/art/Velociraptor-315111266

So what does this mean about our favorite dinosaur thriller film franchise? Well the “raptors” in those films have these inaccuracies: 

  1. Much too big 
  2. Their heads are much too “squashed” 
  3. Their hands are pronated 
  4. No feathers at all 
  5. Organized pack hunting behavior 
  6. Found in Montana, not Mongolia 
  7. Much too intelligent 
  8. Tails are not rigid enough 
  9. General proportions are not correct for a Velociraptor 
  10. Do not act like real animals: Insatiable Hunter Complex

What does this mean? That the animals in the Jurassic Park film series are nothing more than engineered theme park monsters nothing more, nothing less. Doesn’t mean we cannot enjoy them, or the actual animal (which, frankly, I prefer.)

Happy Velociraptor Awareness Day!

Sources: 

http://en.wikipedia.org/wiki/Velociraptor

http://www.prehistoric-wildlife.com/species/v/velociraptor.html

http://en.wikipedia.org/wiki/Dinosaur_intelligence

http://en.wikipedia.org/wiki/Theropoda

Shout out goes to ibiologicalsciences!

10

“you stare at him, and he just stares right back. and that’s when the attack comes.”

Microraptor zhaoianus, M. gui, M. hanqingi

Source: artisticthingem

Name: Microraptor zhaoianus, M. gui, M. hanqingi

Name Meaning: Small Thief

First Described: 2000

Described By: Xu et al. 

ClassificationDinosauria, Saurischia, Eusaurischia, Theropoda, Neotheropoda, Averostra, Tetanurae, Orionides, Avetheropoda, Coelurosauria, Tyrannoraptora, Maniraptoriformes, Maniraptora, Pennaraptora, Paraves, Eumaniraptora, Dromaeosauroidea, Dromaeosauridae, Microraptoria

Microraptor is a fairly famous little dinosaur due to its clear four wings on its fossil. It is known from numerous (over 300 specimens), very well preserved fossils from Liaoning, China, in the Jiufotang Formation. Microraptor lived in the Aptian age of the Early Cretaceous, about 125 to 120 million years ago. Microraptor was distinctive at the time of its discovery for having long, pennaceous feathers, the kind that we typically associate only with birds - solidifying the link between birds and dinosaurs. It was about 1 meter long and only would come up to the calf of a 1.8 meter high person. It had a thick covering of feathers all over its body, with a fan on the end of the tail. Its fossilized melanosomes, or pigment cells, have been analyzed, and found to have black, glossy coloration and iridescence like modern starlings. 

Source: http://www.jsg.utexas.edu/news/2012/03/dinosaur-feathers-evolved-to-attract-mates/

Microraptor, in having four limbs, and a tail fan, was probably able to glide between trees. In fact, the hind wings would have hindered its ability to run on the ground, and would have been confined to an arboreal environment. However, whether or not it could actually fly - meaning, power its own movement through the sky - is fairly controversial. It may have had too primitive of shoulder joints to flap; however it did have a shoulder girdle that could have allowed the wings to be positioned vertically, allowing upstroke of the wing. Wind tunnel experiments have been conducted that Microraptor could actually glide fairly well, regardless of its ability to power its own flight. 

Source: http://green-mamba.deviantart.com/art/072-MICRORAPTOR-ZHAOIANUS-328017378

To glide, it has ben suggested that its hindlimbs and forelimbs were on different levels, such as on a biplane. It could have then glided by launching from a perch, swooping down, and then landing on another tree. Through this model, Microraptor could have potentially achieved powered flight, in addition to gliding. There are some who criticize this hypothesis, though these studies have been insufficient at best. Whether or not the biplane model is correct will require more testing and analysis. On the ground, Microraptor would have dragged its feathers behind him, and only by keeping the wings elevated could it have avoided damaging them. Thus it did not use its forelimbs to capture prey. It may have parachuted from trees to ambush prey on the ground from short distances. Thus, this creature was a mainly arboreal species, spending most o fits life in the trees. 

Source: http://emilywilloughby.com/gallery/paleoart/microraptor-takeoff

This has profound implications for the evolution of flight in birds. It indicates that avian flight evolved from predominantly being powered by all four limbs to being only powered by the forelimbs. Studies of Archaeopteryx, modern birds, and dinosaurs with long primaries on their feet such as Pedopenna indicate that bird flight did undergo this shift. Microraptor has been preserved with remains of food in its stomach as well- specifically it could feed on mammals, lizards, and even tree-perching birds. It also could have eaten fish, due to the evidence of fish scales found in the abdomen. Thus, Microraptor was an opportunistic hunter, feeding on those things it could find in its habitat and glide down to catch. It may have been nocturnal, however its iridescent plumage indicates that this is unlikely. 

Sources: 

http://en.wikipedia.org/wiki/Microraptor

http://www.prehistoric-wildlife.com/species/m/microraptor.html

Shout out goes to artisticthingem​, the artist of the top Microraptor (and a general lover of four-winged dinosaurs, ad my friend)!

Parasaurolophus walkeri, P. tubicen, P. cyrtocristatus

Source: http://fineartamerica.com/featured/a-parasaurolophus-searches-for-a-source-mohamad-haghani.html

NameParasaurolophus walkeri, P. tubicen, P. cyrtocristatus 

Name Meaning: Near Crested Lizard 

First Described: 1922 

Described By: Parks 

ClassificationDinosauria, Ornithischia, Genasauria, Neornithischia, Cerapoda, Ornithopoda, Iguanodontia, Dryomorpha, Ankylopollexia, Styracosterna, Hadrosauriformes, Hadrosauroidea, Hadrosauridae, Euhadrosauria, Lambeosaurinae, Parasaurolophini 

My Sixth Favorite Dinosaur 

There is no real need to explain why Parasaurolophus is cool. It’s one of those dinosaurs that we actually know how it sounded. It had a badass crest and complex social groups. Holy crap. It lived about 76.5 to 73 million years ago, in the Campanian stage of the Late Cretaceous. It lived in many different places - Dinosaur Park Formation in Alberta, Canada; the Kirtland Formation in New Mexico, USA, and the Fruitland Formation in Utah, USA. This is a completely iconic hadrosaur species and it was about 9.5 meters long in the largest individuals. The crest was probably used to distinguish between members of different species and of different sexes, for audible communication, and even thermoregulation. Despite its fame, it’s actually a relatively rare hadrosaur, known from a few specimens. It was a facultative quadruped, and it had high neural spines that increased the height of its back. Skin impressions are known for P. walkeri, showing uniform scales but no other structures. Its crest is connected to its nose, and may or may not have had a skin flap connecting it to the neck, though this is not confirmed. The hollowness of the crest is notable in that it would have permitted sound to pass through it.  

Source: http://www.larryfelder.com/

The type species is known from only one fossil, but the other two species have at least three specimens to their names, with P. tubicen being the largest, and having the most complex air passages in its crest. P. cyrtocristatus was the smallest, with a short rounded crest. P. walkeri had the characteristic long, unrounded crest, and longer upper arms. Charonosaurus has begun to be considered instead of a very closely related genus, another species of ParasaurolophusP. jiayensis, which would make it the first non-North American species. Parasaurolophus was present in many different habitats. In Alberta, it lived along side Centrosaurus, Chasmosaurus, Gryposaurus, Corythosaurus, Gorgosaurus, Edmontonia, Euoplocephalus, and Dyoplosaurus, and was a rare part of the fauna. 

Source: http://www.framestore.com/work/itv-prehistoric-park

In New Mexico, P. crytocristatus lived with Utahceratops, Kosmoceratops, Pentaceratops, Ornithomimus, and teratophoneus. The larger species P. tubicen lived with Alamosaurus, Krotsaurus, Pentaceratops, Nodocephalosaurus, Sauronitholestes, and Bistahieversor. The Kirtland Formation in particular would have been a large floodplain with many conifers. In Utah, it lived in a plateau area near the Western Interior Seaway, a large floodplain with channels and peat swamps, ponds, lakes, and highlands. it was a wet and humid climate and a very diverse environment. Parasaurolophus lived alongside dromaeosaurids, talos, Ornithomimus, Albertosaurus, Teratophoneus, ankylosaurids, Gryposaurus, Utahceratops, Nasutoceratops, Kosmoceratops, and Hagryphus.

Source: Me. This is Max (my boyfriend) playing with the Parasaurolophus model in the Field Museum. One of my favorite photos. 

Parasaurolophus would have eaten plants while chewing, with constantly replaced teeth that were packed together into batteries with hundreds of teeth. It could crop plant life with its beak, and had a narrow beak for selective feeding. It crest was definitely for multiple purposes, and it’s not sure which purpose was the most important in its evolution. Its crest changed with age and was sexually dimorphic, however the major divergences in crest shape and length have been determined as differences in species. A small tubular crest was present in juveniles, with most of the supporting bones also smaller indicating that it had not yet reached maturity. However, Parasaurolophus crests started developing at a younger crest than its relatives such as Corythosaurus, showing how its crest could get so big in its lifespan. 

Source: Me again; Field Museum fossil of P. crytocristatus 

The crest was definitively not used for an aquatic lifestyle or any sort of amphibious lifestyle, and it was not used for moving or supporting the head. It also wasn’t a foliage deflector, a weapon, for housing specialized organs or salt glands, or expanded areas of olfactory tissue, or throwing jets of chemical fire at enemies. Yes. These were all hypotheses proposed over trumpet. I’m as baffled as you are. It was for auditory and visual communication and, given its size, gave a clear visual signal. Given that the animal had large eye sockets and sclerotic rings that means it would have had acute vision and diurnal habits, sight was very important for Parasaurolophus. Based on scans of their inner ears, it was found that they had a very well developed inner ear, and could hear high frequencies, allowing them to hear the chirps of their young as well as the calls made by other members of the species with their crests. Finally, the intense vascularization of the crest would have allowed the brain to be kept cool. 

Source: http://forums.superherohype.com/showthread.php?t=332214&page=2 

I had to. 

Sources: 

http://www.prehistoric-wildlife.com/species/p/parasaurolophus.html

https://en.wikipedia.org/wiki/Parasaurolophus

Shout out goes to riddikulus-darren!